The Empty Room.

My sister and I were discussing Matthew 12:43-45. "When an evil spirit leaves a person, it goes into the desert seeking rest but finding none. Then it says, 'I will return to the person I came from.' So it returns and finds its former home empty, swept and in order. Then the spirit finds seven other spirits more wicked than itself, and they all enter the person and live there. And so that person is worse off than before."

We think Jesus meant that after the Holy Spirit comes inside us, cleanses us from sin and unites us with God we must not let our hearts become empty of the Spirit. Like Israel every morning went out and gathered fresh manna, so we must each day gather wisdom and strength from God through prayer and reading the Bible. Jesus said, "Eat my flesh and drink my blood." He becomes a part of us and fills us.

The man with the evil spirit left himself empty. If we do this then we will become filled with evil and be "slaves to sin," as Jesus also said. If God does not fill us then Satan will. My sister said, "I knew prayer and Bible study were vital, but I didn't know why until now."

Clarke's Commentary on the Bible 
http://bible.cc/matthew/12-44.htm

Into my house - The soul of that person from whom he had been expelled by the power of Christ, and out of which he was to have been kept by continual prayer, faith, and watchfulness.

He findeth it empty - Unoccupied, σχολαζοντα, empty of the former inhabitant, and ready to receive a new one: denoting a soul that has lost the life and power of godliness, and the testimony of the Holy Spirit.

Swept and garnished - As σχολαζω signifies to be idle, or unemployed, it may refer here to the person, as well as to his state. His affections and desires are no longer busied with the things of God, but gad about, like an idle person, among the vanities of a perishing world. Swept, from love, meekness, and all the fruits of the Spirit; and garnished, or adorned, κεκοσμημενον, decorated, with the vain showy trifles of folly and fashion. This may comprise also smart speeches, cunning repartees, etc., for which many who have lost the life of God are very remarkable.